I downloaded the Safari 3.1.2 package for Leopard when I got home. It does require a browser running OSX to access that rather than let's say a Windows version. There's a direct link, but I don't want to get in trouble for doing an end-around with their download scheme. I think it would be OK to transfer it (the end user agreement says something about it being OK once) and I doubt that Apple would get upset over it. It's 38 MB though.
I started thinking about it, and you might try two things. The first would be to run Software Update (the little Apple logo on the top bar and click on "Software Update". I'm thinking if Safari isn't located, it might try and reinstall it as well as install other updates.
The other thing you might try is to install Firefox. You can easily access the Mac version's download package on any machine and transfer the contents to the MacBook. Once Firefox is installed on the MacBook, you can access the Safari package and the download page should recognize that you're on OSX. The OSX version of the Firefox download is on the following link:
http://www.mozilla.com/products/download.html?product=firefox-3.0.3&os=osx&lang= en-US
http://www.apple.com/safari/download/
Good luck and let us know how it turns out.